German Patent Application DE 100 15 773 A1 discloses a specimen holder for aqueous specimens for freezing under high pressure in a high-pressure freezing device. The specimen holder possesses a housing sheath in which a cutout is defined. A specimen retention element is arranged in the cutout of the specimen holder and can be sprayed from both sides, through the cutout, with a coolant. The specimen retention element is constructed from at least one first part and one second part, a recess for specimen reception being shaped into the second part. The second part is pressed with a screw against the first part so that the recess is closed off in pressure-tight fashion. Acting as counter-element for the screw is a further element which comprises a pressure inlet that terminates directly in the sample receptacle. Upon application of high pressure to the specimen holder, the pressure medium that is used thus comes into contact with the specimen.
German Patent Application DE 100 65 143 A1 discloses a specimen holder for a high-pressure freezing device. The specimen holder is made up of at least two shaped parts, detachably joinable to one another, that in the joined state form a receptacle for a specimen. At least one of the shaped parts comprises, on the side facing toward the receptacle, a diamond coating or diamonds themselves. Associated with the shaped part having the specimen receptacle is a further shaped part having a high-pressure conduit. The high-pressure conduits communicates with an orifice that terminates in the specimen chamber. In this fashion, the pressure medium acts directly on the specimen present in the specimen receptacle in order to generate the pressure necessary for high-pressure freezing.
The high-pressure freezing machine of the Balzers company, having the model designation HPM 010, likewise discloses a two-part sample holder in which a separate chamber is constituted. In this apparatus as well, the pressure medium acts directly on the specimen located in the specimen chamber.
The high-pressure freezing device having the model designation “Leica EM HPF” likewise discloses a two-part specimen holder that constitutes a specimen space into which the specimen to be frozen can be introduced. Liquid nitrogen at a pressure of approximately 2100 bar is forced into the freezing chamber by the high-pressure freezing device. The specimen itself is protected by two small aluminum plates, and floats for approximately 40 ms in an alcohol before the liquid nitrogen is introduced under high pressure into the specimen chamber.
The brochure for the “LEICA EM PACT” describes a high-pressure freezing device, having several variants, for retaining specimens for high-pressure freezing. The specimens are placed into a part of the specimen holder that comprises an orifice that is in communication with the pressure medium being used. The pressure medium thus acts directly on the specimen. In addition, these parts of the specimen holders are difficult to produce using mechanical machining processes.